Abstract: An HVAC volume correction controller for a building's HVAC system, and an associated method, for dynamically modulating the volumetric airflow rate entering the building to account for the thermal expansion of air through a blow through heat exchanger. The HVAC volume correction controller: (i) calculates a temperature differential between an air discharge temperature and an air intake temperature; (ii) calculates a volume correction factor, taking into account the thermal expansion coefficient of air and the temperature differential; and (iii) modifies a blower motor speed of the blow through heat exchanger. The HVAC volume correction controller can be retrofitted on existing HVAC systems, or can be integrated with a blow through heat exchanger for new installations.